Molecular Crystal Structure of Acetylacetone at 210 and 110 K: Is the Crystal Disorder Static or Dynamic?

摘要: The molecular and crystal structure of acetylacetone (AA) was studied at 210 110 K in order to reveal the nature hydrogen bond possible disorder. single grown by an situ crystallization from melt using IR laser beam producing a molten zone Lindeman capillary. At both temperatures crystals are orthorhombic (space group Pnma, Z = 4) with molecules having crystallographic mirror plane perpendicular mean plane. intramolecular is characterized O···O distances 2.541(2) 2.547(1) A K, central atom equally distributed over two positions near oxygens. So, AA has distinct potential minima that agreement previous NMR data recent quantum-chemical calculations. lengths C−O C−C cis-enol fragment have averaged values (1.291(1) 1.402(1) K) corresponding superposition enol isomers due ...